The Study Of Automobile Engine's Magneto-Rheological Isolator

The most of isolators which are used for automobile engine are passive rubber mount, while the passive hydraulic isolator is applied for top grade car. Both the isolators whose damping are kept constant are not adjust their dynamic stiffness and damping according to the variation of engine vibration, therefore,it is diffcult to meet the need of wide frequency scope of engine vibration , these shortcomings affect the ride comfort of auto.Aiming at problems being occurred in passive isolator, This paper provides an idea of smart Magneto-Rheological(MR) isolator of taking full advantage of Magneto-Rheological fuild as the working medium. This paper firstly indicates the MR isolator working principle, making a engine hydraulic isolator of domestic-made car as research object, and designs a new type of Magneto-Rheological(MR) isolator . The dynamic performances of the MR isolator such as dynamic stiffness and damping coefficient are tested experimentally.In order to accomplish semi-active electric control system, a open loop control strategy based upon engine rotate speed is presented. the hardware and control program are already designed. Finally, taking the adjusting current model of the electric control system an example, the hardware and software of the electric control system are simulated in the proteus simulation software. Theoretics and simulation stduy demonstrate that comparing with passive isolator , we can gain the better dynamic performance of MR isolator at the scope of wider frequency by changing the pulse width of PWM signal for getting adjustable current in the coil. These works lay solid foundation for the MR mount to application of engine vibration.